I assume when you say you are having trouble swallowing that you mean that your throat is sore. If this is not what you mean, and instead you mean that it is actually physically difficult to open your mouth or hard to swallow (more than just painful), then this could be a sign of a serious throat infection that requires immediate evaluation in an emergency room or by your primary care doctor
On the other hand, if this is just a bad sore throat
then the fact that you also have a stuffy nose suggests to me that this is probably just a viral infection, such as the common cold. The cold can definitely cause a sore throat, especially if you have other symptoms of the cold, such as stuffy nose or cough.
The other major cause of sore throat is strep throat, which is a bacterial infection of the throat that requires treatment with antibiotics. The fact that you have a stuffy nose makes a strep throat infection much less likely (usually with strep throat there are no cold symptoms at all). However, it would be worth being checked out by your primary care doctor who will be able to help distinguish between strep throat and the common cold and prescribe a treatment for you if that is necessary.